Death due to radiation
Depending on the amount as well as the period of exposure, radiation can cause instantaneous death or delayed death. Tissues that divide rapidly are most vulnerable because their DNA is more sensitive. This explains the sensitivity of tissues such as bone marrow and the epithelial cells of the gastro-intestinal system, that divide rapidly.
If the radiation dosage is low, or if the person survives the initial phase of radiation disease, damage to the genetic content of the cells could later cause tumours or leukaemia. This can take as long as 10 years or more. In a similar manner damage to the reproductive organs and especially the embrionic cells could cause genetic abnormalities in babies. The descendants of the survivors of the atomic bomb explosions in Japan are living proof of the devastating effect of radiation. In controlled situations radiation is an integral part of the treatment of malignant tumours (radiotherapy).